Finite MathThe purchases made by customers at a convenience store are normally distributed, with a mean of $5.50 and a standard deviation of $3.50. What is the probability that a randomly chosen customer makes a purchase between $2.00 and $9.00?
March 9, 2014

mathThe volume of a cone is three hundred cubic kilometers. If the radius of the base is 9 kilometers, what is the height of the cone? Use three point one four for pi. Show your work and round to the nearest tenth.
August 27, 2010

chemistryCalculate the wavelength (in nanometers) of a photon emitted by a hydrogen atom when its electron drops from the n = 4 state to the n = 3 state.
March 23, 2010

chemistry 106Methanol, ethanol, and n-propanol are three common alcohols. When 1.00 g of each of these alcohols is burned in air, heat is liberated. Calculate the heats of combustion of these alcohols in kJ/mol. (a) methanol (CH3OH), -22.6 kJ (b) ethanol (C2H5OH), -29.7 kJ (c) n-propanol (...
March 3, 2010

chemistry 106A 0.1589 g sample of solid magnesium is burned in a bomb calorimeter that has a heat capacity of 1769 J/°C. The calorimeter contains exactly 251 g of water, and the temperature increases by 1.126°C. Calculate the heat given off by the burning Mg, in kJ/g and in kJ/mol.
March 3, 2010

chemistry 106Calculate the work done if a gas is compressed from 8.3 L to 3.3 L at constant temperature by a constant pressure of 3.0 atm, and give your answer in units of joules. (1 L · atm = 101.3 J)
March 3, 2010

chemistry 106Determine the amount of heat (in kJ) given off when 2.23 multiplied by 104 g of ammonia are produced according to the following equation. Assume that the reaction takes place under standard-state conditions at 25.0°C. N2(g) + 3 H2(g) 2 NH3(g) ΔH°rxn = -92.6 kJ
March 3, 2010

chemistry 106Which of the following standard enthalpy of formation values are not zero at 25°C? (Select all that apply.) H2(g) N2(g) Au(s) Be(s) H20(g) Ne(g)
March 3, 2010

chemistry 106Dry air near sea level has the following composition by volume: N2, 78.08 percent; O2, 20.94 percent; Ar, 0.93 percent; CO2, 0.05 percent. The atmospheric pressure is 1.00 atm. (Hint: Since volume is proportional to the number of moles present, mole fractions of gases can be ...
March 1, 2010

chemistry 106Nitroglycerin, an explosive compound, decomposes according to the equation below. 4 C3H5(NO3)3(s) 12 CO2(g) + 10 H2O(g) + 6 N2(g) + O2(g) Calculate the total volume of gases when collected at 1.2 atm and 25°C from 1.3 multiplied by 102 g of nitroglycerin. What are the ...
February 28, 2010

chemistry 106calculate the pressure exerted by 1.00 moles of CO2 confined in a volume of 5.00 L at 450. K. Compare the pressure with that predicted by the ideal gas equation.
February 28, 2010

chemistry 106A gas-filled balloon having a volume of 1.50 L at 1.2 atm and 25°C is allowed to rise to the stratosphere (about 30 km above the surface of Earth), where the temperature and pressure are -23°C and 3.00 multiplied by 10-3 atm, respectively. Calculate the final volume of...
February 28, 2010

chemistry 106The pressure of 6.0 L of an ideal gas in a flexible container is decreased to one-half of its original pressure, and its absolute temperature is decreased to one-seventh of the original. What is the final volume of the gas?
February 28, 2010

PRE*******ALGEBRAWRITE A FUNCTION RULE TO DESCRIBE EACH SITUATION. PLEASE HELP I DO NOT UNDERSTAND THIS AT ALL. The number of pounds p(z)as a function of the number of ounces z. The selling price s(c)after a 45% markup of an item as a function of the stores' cost c. The total number of ...
April 30, 2009

mathThe medians are 33 and 36 then you add 33 and 36 and divide the solution of the numbers by 2 and you should get 34.5 or 34 1/2.
April 30, 2009

Math Pre AlgebraFind the simple interest. $900 deposited at an interest rate of 3% for 5 years. $1,348 deposited at an interest rate of 2.5% for 18 months.
April 14, 2009

ScienceI have two questions. How can an atmosphere affect the temperature of a planet's surface? If a planet had a surface with craters but no other features, what could you say about the inside of the planet?
April 14, 2009

mathso if my question is find the dimensions of a box that will hold twice as many cubes as a box that is 2 by 6 by 4 a] volume of original box: 48 b]volume of new box is :96 c] dimensions of new box is 12 by 4 by 2
October 7, 2008

chemistryok this is what i have gotten: 3Fe2O3(s)+9CO(s)-->6Fe(s)+9CO2(g) 2Fe3O4(s)+CO2(g)-->3Fe2O3(s)+CO(g) 6FeO(s)+2CO2(g)-->2Fe3O4(s)+2CO(g) but the desired reaction is in a one to one ratio, and also the CO(g) is on the left side in the desired reaction. does that mean i ...
March 26, 2008

To:Jasmine20Guru is like a master. Did you had help with the questions and answers of HINDU RELIGION? I mean the one you posted that you need another religion, not your religion did you got help? I think jasmine20 is not on jiskha I HAVE TO TRY AND FIGURE OUT SOME MORE STUFF FOR MY FINAL ...
December 29, 2006

Social Studies Homework (About USA And Canada)I need help with one question and I need one question answer checked! Social Studies Homework: 1)What are the two main languages of USA? Answer: English and Spanish 2)What are the two main languages of Canada? (Please give an direct answer for question 2 and don't write ...
December 29, 2006

Please Help Me With My Math HomeworkI wrote my math homework questions. It's in Jiskha Homework Help Forum In: Name:Tanisha Subject:Math Thank You! I already replied, you don't need to make a new question asking someone to answer...... Thanks for the answer! It was a good help! the product of 7_ ,4_ , ...
December 26, 2006

MathI need help with my math homework.I searched for homework help forums and I found the Jiskha Website on the Google Website so this is my first time.I am new. Math Homework: What is the value of number 3 in 2,539? What is the value of number 9 in 4,879 What is the of number 6 ...
December 26, 2006

inclusive languageCan you please verify if I have done this correctly 1. Each advisor was contacted by his students. my answer Each advisor was contacted by their students. or Each advisor was contacted by his or her students. His or her students, not their students (because you are saying EACH...
November 22, 2006

inclusive languageCan you please verify if I have done this correctly 1.The directors and their wives met the stockholders for a night on the town. my answer The directors and their spouses met the stockholders for a night on the town. You are correct.
November 22, 2006